Jose Onorbe
Fulbright Fellow, UCI

Feedback from Massive Stars in Dwarf Galaxy Formation

I will present hydrodynamical simulations of the formation of dwarf galaxies starting from cosmological initial conditions at high redshift. In these simulations, a novel numerical implementation of stellar feedback resulting from momentum imparted to the ISM by radiation, supernovae, and stellar winds has been used (Hopkins et al. 2011). Our final objects have structure and stellar populations consistent with observed dwarf galaxies. First results indicate that feedback from massive stars plays a critical role in shaping the galaxy mass function, the structure of the interstellar medium (ISM), and the low efficiency of star formation.

Greg Dobler

From Hazes to Bubbles: an Enormous Eruption from the Heart of the Milky Way

Recently we have discovered an enormous feature in full sky maps from the Fermi Gamma-Ray Space Telescope. The emission is centered on the Galactic center, is elongated in latitude by a factor of roughly two, and extends a full ± 10 kpc away from the Galactic plane making it one of the largest structures in the Galaxy. This emission is generated by a cloud of electrons with a very hard spectrum inverse Compton scattering low energy photons up to Fermi energies. It has come to be known as the "Fermi Haze" or "Fermi Bubbles" and represents a unique opportunity to get a close up view of energetic phenomena that occur in the centers of galaxies. I will go through the observational evidence for the haze/bubbles at multiple wavelengths in Fermi, WMAP, and Planck data and describe how recent advances in our understanding of the emission suggest that the black hole at the center of our Galaxy was once the launching site for an accretion driven jet which gave rise to the bubbles we see today.